Electric circuit interrupter



ELECTRIC CIRCUIT INTERRUPTER Filed NOV. 19, 1951 Gusta? AM Juhlih; bg www His A'bcor'neg.

l5 ing chamber or explosion pot.

i Patented-Mar. 2,1, 1933 UNITED STATES `PATENT OFFICE GUSTAF JUH'LIN, OF TIMPERLEY, ENGLAND, ASSIGNOR TO GENERAL ELEUI'RIC COMPANY, A CORPORATION 0F NEW YORK ELECTRIC CIRCUIT INTERBUPTEB VApplication jiled November 19, 1931, Serial No. 576,163, and in Great Britain December 18, 1880. V

Ihis invention relates to electric circuit lnterrupters of the expulsion type in which the contacts are immersed in oil or other insulating liquid and separate within an arc- A principal object of .this invention isthe provision. of an improved circuit interrupter of the above expulsion or oil-blast typeV l which shall be simple andrugged inconstruc- '1o tion and positive and eilicient'in operation.

In accordance with the present invention one or more channels transversely positioned with respect to the` arc drawn .between the contacts -communicate with the arcing chamber or explosion pot indirectly through a vsecond or auxiliary chamber which is arp ranged to provide a reserve supply of oil adequate for quenching the arc, Preferably, the arcin chamber .or explosion pot is of comparatlvelyY small dimensionsv and is .con-

structed integrally with the auxiliary chamber, the whole beingl immersed in the main body of oil contained inthe oil tank in which other`- parts or other contacts of the circuit 2'5 interruptery are located. The moving contact is arranged to-be moved upwards and downwards in a well known manner with respect to the xed contactwithin the arcing chamber. for closing and opening the circuit breaker, the insulating wall forming the base 'of the two chambers which communicate with one'another adjacent the upper part thereof. This invention will be more fully set forth in the following description, referring to the 85 accompanying drawing, and the features of novelty which vcharacterize this invention vwill be pointedout with particularity in the claims annexed to and forming a part of this.

. specification. l To enable the invention to be clearly under-y stood it will now be described with reference to the accompanying drawing, of which Fig. lis an elevational view, partly in section, of

. a part of a circuit'interrupter constructed in' 'accordance with the present invention, and Figs. 2 and 3 areY detailedv plan views of circuit` interrupter structure.

Referring to the drawing, and more par-v ticularly'Fig. 1, the main arcing chamber is indicated at 1 in which is mounted the fixed contact 2 of the circuit interrupter which may be of any suitable type. Preferably, however, contact 2 is of the well known resilient socket or selfaligningtype. The movable contact indicated at 3v is of the plug type, the contact 3 being carried in a well known manner upon a conduct-ing bridge 4 at the Vother end of which may be a simllar contact cooperating with a fixed contact in another arcing chamber (not shown) A part of the main oil tank containing insulating liquid in which the above structure is immersed is indicated at .5.

The main arcing chamber 1 is formed within a casing comprising a metal casting 5 havlng a cylindrical wall 6 preferably lined with i a tube 7 of refractory insulating material, said arcing chamber being closed at its lower end by the insulating wall 8, which will be hereafter described. The upper portion of the casting 5 is provided with connecting means, as 6'-, for supporting the explosion chamber structure and electrically connectingthe contact 2 through the metal casting to the lead-in conductor 2. A portion of the wall 6 comprises a partition likewise forming within the casing an auxiliary chamber or oil reservoir 9`which communicates with the main chamber 1 by the opening ladjacent the top of thetwo chambers.

The insulating wall 8 closes the lower ends of both lchambersvl and 9 and has a main passage 11 through which the plug contact 3 is movedfor closing and opening the circuit, said passage 11 providing a reasonable into the main oil tank 5 and at the right into the vertical exhaust duct 14, which communicates with the oil reservoir chamber 9.

The insulating wall 8 in which the pas-l sage 11-12 and the channels 13 and duct 14 are formed is conveniently constructed of a 100 plurality ,of plates. Three plates l5, one of which is shown separately in plan in Fig. 2, two plates 16, one of which is shown separately in Fig-3, and a base or cover plate 17 are stacked as hereinafter described to complete the structure.

Each plate 15 (Fig. 2) has a perforation 11 through which the plug contact 3 moves, and an arcuate perforation 14. 'Each plate 16 (Fig. 3) has an opening 18 which is conveniently of the shape shown, said opening having a portion at the right which corresponds with the perforation 14 in each of the plates 15, a central narrow portion through which the moving contact 3 passes and a flared mouth through which the streams of oil emerge into the main oil tank. The plates 15 and 16 and also the plate 17 are provided with holes 19 to enable the several plates 15, 16 and 17 to be bolted or secured together in any suitable manner, as by six bolts, three of which are indicated in dotted lines at 20 in Fig. 1. In some cases .each channel 13 may be divided on the right side of the main passageway 11 as by the provision-.of insulating washers 21 surrounding and located by an insulating peg 22 the ends of which are en aged in recesses in the upper plate 15 and t e lowerxnost or cover plate 17, as shown.

By reason ofthe auxiliary chamber 9 it will be noted that the latter will contain a relatively large body of oil which is forced across the moving contact when the circuit breaker is opened, due to the pressure caused b the arc which is formed in the arcing chamber 1, so that the arcing chamber may be made of desirably small dimensions.l

A particular advantage of the above arrangement residesin the fact that'the highly ionized and hot conducting gases'generated by the arc are not readily mixed with the comparatively cool oil which is forced from' the auxiliary chamber 9' and blasted in separate jets transversely of the arc stream. The gas generated within the main arcing chamber 1, while subjecting the oil in the auxiliary chamber 9 to highpressure, is not aii'orded opportunity to mix with the oil blast until the oil is practically exhausted from the chamber 9. However, in practice the arc is generally extinguished within a very short tlme at a current zero, the initial part of the oil blast through the transverse passages 13 so thatexhaustion of oil from the chamber 19 before circuit interruption is unlikely. It will be apparent, of course, that the oil capacity of the auxiliary chamber9 may be chosen in accordance with the current interruptin 'characteristics involved so that there w1ll be an adequate reserve of comparatively cool and Afresh oil having high dielectric strength for the oil blast. By arranging the opening 10 at the. upperpart of the communicating arcduring Laoaaov' ing and auxiliary chambers, the oil within the auxiliary chamber 9 is subjected to full pressure while minimizing any tendency for hot arc gases from the arcing chamber to `mingle therewith.

lt should be understood that this invention is not limited to specific details of construction and arrangement thereof herein illustrated, and that changes and modifcacontaining insulating liquid in amount suicient to interrupt the circuit, the liquid in said auxiliary chamber being subjected to pressure generated within said arcing chamber and means directing insulating liquid auxiliary chamber across the arc formed between saidcontacts.

2. An electric circuit interrupter comprising explosion chamber structure immersed in an insulating liquid including an arcing` chamber and an auxiliary chamber containing insulating liquid in amount suificient to interrupt the circuit, contacts separable within .said arcing chamber arranged so that pressure is generated within said chamber by arcing, and means communicating pressure from said arcing chamber to said auxiliary chamber effecting a blast of insulating liquid from said auxiliary chamber across the arc formed between said contacts.

3. An electric circuit interrupter of the oil-blast type comprising an arcing chamber,

contacts separable in an insulating liquid within said chamber, an auxiliary chamber containing insulating liquid, said chambers communicating adjacent the upper parts thereof so that liquid within said auxiliary chamber is subjected to the pressures generated within said arcing chamber, and

means directing insulating liquid from the' lower part of said auxiliar chamber across1 the arc formed between sald contacts.

4.11m an electric circuit interrupter ofthe oil-blast type, explosion chamber structure l comprising a casing having a partition dividing the same into an arcing chamber and an auxiliary chamber, said partitionhaving an opening adjacent the topipermitting commumcation between said chambers, insulatmg liquid filling said chambers, contacts separable within said arcing chamber, and insulating plates forming with said casing a passage leading from the lower part of said auxiliarychamber communicating with a plurality of passages extending transversely of under influence of said pressure from said T the arc dra-wn between said contacts, said arc generating pressure within said arcing chamer causing a blast of insulating liquid from said auxiliary chamber through said trans- 5 verse passages and across the arc interrupting the circuit.

5. An electric circuit interrupter of the oil-blast type comprising explosion chamber structure immersed in an insulating liquid, contacts separable within said structure generating pressure, and means forming a plurality of passages directing blasts of insulating liquid from said structure transversely across the arc drawn between said contacts including a, plurality of stacked insulating plates, each of saidplates having apertures in alinement forming a passage from said structure, and other apertures in alinement forming a passage through which one of said contacts may move, alternate plates forming apertures exhausting from said first-named passage to the exterior of said structure transversely of the arc drawn between said contacts. v In witness whereof, I have hereunto set my hand.

GUSTAF ADOLF JUBILIN. 

